| Revolution on gastroenterology had been aroused since Helicobacter pylori (Hp) was separated and cultured from gastric mucous by B Marshall and R Warren in 1983. A new epoch had started then. It has been already accepted by international medical science that Hp which infectious rate is the highest among all bacteria is the immediate cause of chronic gastritis and peptic ulcer. Hp was considered the first class of carcinogenic factor and the common etiological factor by WHO in 1994. It is showed by many researches that Hp infection is associated with gastric ulcer and superficial gastritis, atrophic gastritis and gastric mucous lymphoma closely. Although Hp has a closely relationship with chronic infection , only a few of patients develop into peptic ulcer and even fewer patients would develop into gastric cancer.It is found that Hp acts at the initiation stage of the forming process of gastric cancer and Hp is considered an initial factor of gastric development. In the past, researches on relationship between Hp and gastric forming have been concentrated mainly on the aspect that Hp causing ultra - proliferation of gastric mucous epithelial cells. And it was thought that the gastric cancer was developed by cells " assemblage resulted from infinite proliferation. But recent studies showed that Hp infection might cause abnormality of proliferation and apoptosis of gastric mucous epithelial cells and disequilibrium between them play an important role in the development of gastric cancer. In the forming process of gastric cancer, there is not only cell proliferation but also cell apoptosis. But in the tumor cells there are ratio imbalanceIt is confirmed that Hp infection causing abnormality of proliferation and apoptosis of gastric mucous epithelial cells associates with gastric cancer closely.But the carcinogenic mechanism of Hp has not been clarified yet. The biological characteristics of Hp associated gastric diseases need deeply studies.It is firstly suggested by Kerr in 1972 that Apoptosis is an active gene controlled death procedure and this is becoming a new hot spot of life science research at present.Many physiologic and pathologic factors take parts in cell apoptosis and the progress initiates by apoptosis associated genes. Many inflammation medium and cell factors could affect this progress.It is known now that there are many kinds of oncogenes taking parts in controlling apoptosis of gastric cancer, especially bcl - 2/bax genes which are considered having the most closely relationship with cell apoptosis of gastric cancer. But the relationship between Hp infection and apoptosis associated, bcl - 2/ bax, genes in the development of gastric cancer is still not completely reported. In this study, in order to find out the influences on cell apoptosis of gastric mucous epithelia cells by Hp infection and to bring light on some biological characteristics of Hp associated gastric diseases, TUNEL technique was used to study biologically on apoptosis of normal gastric mucous, Hp associated gastric diseases and gastric cancer. At the same time, expressions of apoptosis associated genes, bcl - 2/bax, in Hp related gastric diseases were detected by immunohis-tochemical technique. Through discussing on the relationship between Hp infection and the expression of Bcl - 2/Bax protein, we found the possible molecular mechanism of Hp infection causing imbalance between cell apoptosis and proliferation of gastric epithelial cells resulting in the formation of gastric cancer.The certain mechanism of Hp infection causing cell apoptosis is still not clear yet. Except gene controlling, it is suspected that there might be many induce factors that are related such as Hp developed toxin, CagA( cytotoxin - associated gene A) , and cytokine or oxygen - derived free radicals which are released in inflammation reaction after Hp infection.Interleukin - 8 ( IL - 8 ) , located on 4ql2 - 21 of human being chromosome, was the first chemokine that Yoshimur found in 1987. It is 5. 2kb long, consisting 4 exons and 3 i... |
